1. Field of the Invention
The present invention relates a hinge and an open-cover type personal computer including the same.
2. Description of the Related Art
A note-type personal computer is usually designed to have a mechanism which makes it possible to lift an upper cover up from a main body with small force, and keep the upper cover open at a certain angle relative to the main body.
FIG. 7 is a perspective view illustrating a conventional note-type personal computer 100 suggested in Japanese Patent Application Publication No. 2004-3594.
As illustrated in FIG. 7, an upper cover 101 into which a liquid crystal display unit is incorporated is supported at opposite ends thereof relative to a main body 102 such that the upper cover 101 can open and close relative to the main body 102.
One of supporters 103 is comprised of a resistive hinge 104 so as to produce a force for stopping rotation of the upper cover 101.
The other supporter 105 is comprised of a torsion coil spring 106. The torsion coil spring 106 makes it possible to open the upper cover 101 with small force, and acts as a dumper when the upper cover 101 is closed relative to the main body 102.
In the conventional note-type personal computer 100, a force for stopping rotation of the upper cover 101 is dependent on a weight of the upper cover 101. For instance, if the upper cover 101 is 850 grams in weight, there are used the resistive hinge 104 having a resistance of about 6 kgf/cm, and two torsion coil springs 106 compensating for gravitational force of the upper cover 101 to fall down, in order to prevent the upper cover 101 from falling down due to its own weight and keep the upper cover 101 open at a predetermined angle (generally, in the range of 80 to 160 degrees) at which a viewer can see the upper cover 101 most clearly. However, the conventional note-type personal computer 100 is accompanied with a problem that since gravitational force of the upper cover 101 of about 5.8 kgf/cm at maximum is added to the resistance of resistive hinge 104 of 6 kgf/cm, a force for stopping rotation of the upper cover 101 is reduced when the upper cover 101 is open at 150 degrees or greater, and resultingly, the upper cover 101 falls down due to its own weight, and that if the resistive hinge 104 is designed to have a greater resistance, the upper cover 101 would not fall down due to its own weight, but it would be necessary to apply a greater force to the upper cover 101 for opening the same.